Effects of hematodinium infection on the Norway lobster, nephrops norvegicus (L.)

The Norway lobster (Nephrops norvegicus) is one of the most valuable shellfish resources in the north east Atlantic ocean and considerable knowledge exists with regard to its biology and life history. During the late 1980s, populations of N. norvegicus were shown to harbour an infection by a parasite of the genus Hematodinium (Dinoflagellata: Syndinidae). Although studies on the pathology, progression and prevalence of infection have since been carried out, considerable gaps exist in our knowledge of the effects of parasitism on host life history and cycling of the parasite in the field. This study aims to develop techniques for monitoring Hematodinium infection in natural populations of N. norvegicus and to study the interactions between parasite-induced pathological changes and the life history of host animals. This study has greatly increased our understanding of the complex relationship between Hematodinium parasites and their hosts. By linking biochemical and physiological data to effects observed in the field, it has been shown that Hematodinium infection may provide an excellent model system for studying stress responses in aquatic invertebrate hosts. The study has described in much greater detail than before the effect of parasitism on host lobsters, and has related these effects to the moult cycle and to host condition. Furthermore, it has shown how changes in host behaviour and locomotion during infection may be directly or indirectly linked to biochemical and physiological changes brought about by infection. The implications of these changes in the life history N. norvegicus for the availability of infected lobsters to be captured by trawlers and predators is discussed